ROSEBURG, Ore – For the first time ever, tiger trout will soon be swimming in Diamond Lake’s crystal blue waters.

Biologists hope these sterile trout prey on any invasive fish once they are large enough next spring. Tiger trout are a hybrid between a female brown trout and a male brook trout.

Diamond Lake will get 5,000 tiger trout in the six to seven-inch size range the week of June 6 with another 13,000 fingerlings a few weeks later. ODFW purchased the trout from Cold Springs Trout Farm, a private Utah hatchery, through grant funding from the Umpqua Fisheries Enhancement Derby and Sport Fish Restoration.

Another 300,000 rainbow trout fingerlings also will be stocked the week of June 6 and should be legal-sized this fall. Rainbow trout fishing right now is excellent and the fish are biting well.

Tiger trout angling is catch-and-release only while the rainbow trout limit is five legal-sized (eight inches) trout per day with two daily limits in possession and just one trout per day over 20 inches.

ODFW treated Diamond Lake with rotenone in 2006, ridding it of an estimated 90 million tui chub, an invasive bait fish that reproduces rapidly. In 2008, biologists discovered golden shiners, another illegally introduced bait fish in the lake. Late last fall, a single tui chub was found during routine monitoring.

“We all felt tiger trout were the way to go,” said ODFW District Fish Biologist Greg Huchko. “Because these fish are sterile, there isn’t a risk to North Umpqua River native fish. And once they’re about 14 inches, they should begin to prey on golden shiners and tui chub.”

Huchko hopes the tiger trout will take advantage of shiners’ and tui chubs’ life history. Both are minnows that spawn at smaller physical sizes and prefer to congregate in large schools close to shore.

“Tiger trout aren’t afraid to hunt in just a few inches of water, particularly in the early morning and late evening, so we’re hoping they’ll follow the shiners, and any chub, into the shallows,” Huchko said.

Tomorrow, June 1, ODFW seasonal employees begin intensive fish species monitoring at Diamond Lake with funding help from partners.

The two technicians will remove golden shiners and any tui chub via beach seines, fyke nets, electro-fishing, and trap nets. They will also monitor the tiger trout and rainbow trout populations by creel and diet surveys and operate a smolt trap near the lake’s outlet.